That would be my assumption. I'm not sure what the architecture is on the App Runner, but I would assume that it is a x86/amd64 CPU. I too am working on an Apple Silicon chip and whenever I deploy, I do need to take into consideration the difference in the chipsets. I normally catch any issues in my CI/CD (which runs on an Intel CPU) so it hasn't been too big of a deal here.
Good point. I think if I were to avoid the initial query, I would leave the post index action blank and have the turbo frame tag call an entirely different route. That should work as well.
Where are you receiving this error? All of the videos I use are using the H.264 video codec along with AAC Audio codec. If you're getting this error when transcoding the video, what version of ffmpeg do you have? I have a few different versions that are running on various machines that have done the transcoding.
That's going to greatly depend on the encoding quality. Check out Handbrake to see some of the settings and determine what is acceptable encoding quality. You can also look at the command running in the terminal (with top or htop) to get the ffmpeg settings used.
I don't think that I've tried using the M1 directly to do the encoding. I've always tested within a docker container since that's where I do most of my development.